Biocompatible Insect Control-agents (herein called "BICs")--i.e. pest control agents which pose little hazard to humans and to the environment have been known for many years and their number is steadily growing. BIC can act as insect behavioral modifiers (such as feeding and oviposition detergents, repellents, etc.), hyperactivity inducers, knock down agents, physical barriers or physical poisons [J. J. Kabara (1987), Fatty Acids and Esters as Antimicrobial/insecticidal Agents. In G. Fuller and D. Nees (eds.): Ecology and Metabolism of Plant Lipids. Washington: ACS, pp. 220-238].
BIC are related to many chemical classes such as certain carboxylic acids, alcohols, esters, ethers, amides, terpenoids, limonoids, sulfides and heterocyclic compounds [D. A. Carlson (1978) Repellents. In: Kirk. Othmer Encyclo. Chem. Technol, pp. 786-805].
Increasingly, BIC are used as alternatives for neurotoxic insecticides mainly for human protection with (DE U.S. Pat. No. 3,211,632) and without (Carlson 1978) oils but also for veterinary purposes and to control food and store insects (IL Patent No. 53570).
Many BIC possess properties which are highly desirable also for plant protection, mainly on account of their rapid and safe action. However, most BIC cannot be applied to foliage due to their phytotoxic nature (Kabara 1987). One solution to this problem is to formulate BIC in a way which decreases their phytotoxicity and at the same time preserves or promotes their activity against the target pest.
The term agricultural oils [L. S. Helser and F. W. Plapp (1986) Combinations of Oils and Similar Compounds with Insecticides: Effect on Toxicity and Leaf Residues. South. Entomol.: 75-81] is used rather loosely to describe different mixtures of lipophilic chemicals [such as mineral oils, vegetable (corp) oils (hereinafter called "VO") and silicones], which differ enormously in their on-leaf behavior [D. Veierov, M. J. Berlinger and A. Fenigstein (1988), The Residual Behavior of Fenpropathrin and Chlorpyrifos Applied as Aqueous Emulsions and Oil Solution to Greenhouse Tomato Leaves. Med. Fac. Landbouww, Gent 53:1535-1541], Vegetable oils (VO) have been used for many years directly for control of weeds, fungi and insects, and as solvents and additives in conventional pesticide formulations.
Oils of various types were found to increase penetration of pesticides into leaf interiors (Veierov 1988). This, in part, explained the enhanced phytotoxicity of herbicides when applied to foliage together with oils.
Many types of VO can retard foliage penetration of pesticides when the two ingredients are properly formulated together. Moreover, the pesticide residue is retained above the leaf surface available to the insect and protected from weathering [D. Veierov and M. Ramakom (1991) Optimization of Foliar Applied Formulations for the Control of the Tobacco White Fly Under Field Conditions. Final Report to the U.S. Agency for International (AID) Development: 140].